THREE-DIMENSIONAL FORMING APPARATUS AND THREE-DIMENSIONAL FORMING METHOD
A three-dimensional forming apparatus includes: a material supply unit that arranges a green sheet obtained by forming a sintering material in which metal powder and a binder are kneaded into a sheet shape on a stage; a first heating unit that supplies first energy transpiring a part of the green sheet; a second heating unit that supplies second energy capable of sintering a part of the green sheet; and a driving unit that is able to move the first heating unit and the second heating unit three-dimensionally relative to the stage, wherein the first energy is supplied from the first heating unit to the green sheet so that a sintering region to be sintered with the second energy supplied from the second heating unit in the green sheet supplied to the stage by the material supply unit is surrounded.
This application claims priority to Japanese Patent Application No. 2014-206971 filed on Oct. 8, 2014. The entire disclosures of Japanese Patent Application No. 2014-206971 is hereby incorporated herein by reference.
BACKGROUND1. Technical Field
The present invention relates to a three-dimensional forming apparatus and a three-dimensional forming method.
2. Related Art
In the related art, a method described in JP-A-2002-97532 is disclosed as a manufacturing method of simply forming a three-dimensional shape using a metal material. JP-A-2002-97532 discloses, as a method of forming a composite fabricated object of metal and ceramics, a method of superimposing a metal tape in which a metal fine powder is formed in a tape shape in a ceramics tape in which a ceramics fine powder is formed in a tape shape, radiating a laser beam from the metal tape so that the cross-sectional shape of the composite fabricated object is formed, melting the metal tape, and diffusing the ceramics in the metal to form the composite fabricated object.
A method described in JP-A-2008-184622 is also disclosed. In the method of manufacturing a three-dimensional fabricated object disclosed in JP-A-2008-184622, a metal paste including, a metal powder, a solvent, and an adhesive thickener in a raw material is formed into material layers in a layered state and used. A metal sintered layer or a metal melted layer is formed by radiating a light beam to the material layers in the layered state. Then, the sintered layers or the melted layers are stacked by repeating the forming of the material layers and the radiation of the light beam, and thus a desired three-dimensional fabricated object can be obtained.
In the methods of forming the composite fabricated object and the three-dimensional fabricated object described in JP-A-2002-97532 and JP-A-2008-184622, a part of the raw material is sintered or melted by radiating the laser to a fabrication region. However, since heat applied to the fabrication region is also transferred to the unsintered or unmelted raw material in the region other than the fabrication region, especially near a boundary with the fabrication region and an unnecessary sintered or melted portion remains in the margin of the fabrication region, there is a concern of a desired shape being rarely obtained precisely.
SUMMARYAn advantage of some aspects of the invention is to obtain a three-dimensional fabricated object with a precise shape according to an apparatus and a method capable of radiating heat energy only to a desired shape region.
The invention can be implemented as the following forms or application examples.
Application Example 1A three-dimensional forming apparatus according to this application example includes: a material supply unit that arranges a green sheet obtained by forming a sintering material in which metal powder and a binder are kneaded into a sheet shape on a stage; a first heating unit that supplies first energy transpiring a part of the green sheet; a second heating unit that supplies second energy capable of sintering a part of the green sheet; and a driving unit that is able to move the first heating unit and the second heating unit three-dimensionally relative to the stage, in which the first energy is supplied from the first heating unit to the green sheet so that a sintering region to be sintered with the second energy supplied from the second heating unit in the green sheet supplied to the stage by the material supply unit is surrounded.
According to the three-dimensional forming apparatus of this application example, the precise sintering region can be formed by transpiring and removing the green sheet so that the sintering region to be sintered with the first energy, which is a part of the three-dimensional fabricated object, is surrounded. Accordingly, it is possible to form the precise three-dimensional fabricated object.
In this application example, the sintering in “capable of sintering” refers to transpiring of a binder of the supply material due to the supplied energy and metal bonding between the remaining metal powder by the supplied energy by supplying the energy to the supply material. In the present specification, a form of the melting and bonding of the metal powder will be described as sintering performed by supplying the energy and bonding the metal powder.
Application Example 2In the three-dimensional forming apparatus according to the application example described above, an output of the first energy is different from an output of the second energy.
According to this application example, it is possible to easily control and supply desired energy for transpiring and desired energy for sintering the green sheet which is a raw material.
Application Example 3In the three-dimensional forming apparatus according to the application example described above, the first heating unit and the second heating unit are laser radiation units.
According to this application example, it is possible to radiate the energy to a precise position, and thus it is possible to obtain the precise three-dimensional fabricated object. Further, it is possible to easily control an energy output.
Application Example 4A three-dimensional forming method according to this application example includes: supplying a green sheet obtained by forming a sintering material in which metal powder and a binder are kneaded into a sheet shape; forming a single layer by transpiring and removing a part of the green sheet through radiation of first energy to the green sheet to form a removed portion and by radiating second energy toward the green sheet and sintering a part of the green sheet to form a sintered portion; stacking the single layer formed in the forming of the single layer as a first single layer and stacking the single layer as a second single layer in the forming of the single layer; and removing an unsintered portion from a stacked body including a three-dimensional fabricated object in which the sintered portions are stacked by repeating the stacking of the single layer a predetermined number of times.
According to the three-dimensional forming method of this application example, an unintended portion is prevented from being sintered due to the radiation of the second energy in the sintering of the part of the green sheet. Therefore, by transpiring the part of the green sheet with the first energy in advance and forming the removed portion, it is possible to form a precise sintering region. Accordingly, it is possible to form the precise three-dimensional fabricated object.
By performing the forming of the single layer by causing the unsintered portion to remain and stacking the green sheet, the green sheet of the lower layer prevents the green sheet from being deformed in the gravity direction while the single layer is formed. Thus, it is possible to form the precise three-dimensional fabricated object.
Application Example 5In the three-dimensional forming method according to the application example described above, in the removing of the part of the green sheet, the removed portion is formed so that a region in which the sintered portion is formed in the sintering of the part of the green sheet is surrounded.
According to this application example, the material of the green sheet is removed from the circumference of the sintered portion in the sintering of the part of the green sheet. Thus, it is possible to obtain the precise three-dimensional fabricated object.
Application Example 6In the three-dimensional forming method according to the application example described above, the first energy and the second energy are lasers, and the first energy and the second energy are different in a laser output or a laser wavelength.
According to this application example, it is possible to radiate the energy to a precise position, and thus it is possible to obtain the precise three-dimensional fabricated object. Since the desired energy for transpiring the green sheet which is a raw material and the desired energy for sintering the green sheet can be easily controlled in the laser radiation unit, it is possible to obtain the three-dimensional fabricated object with high quality.
Application Example 7In the three-dimensional forming method according to the application example described above, the removing of the part of the green sheet includes forming a splitting portion that splits the unsintered portion to be removed in the removing of the unsintered portion into a plurality of pieces.
According to this application example, by splitting the unsintered portion to be broken and removed by the splitting portion, it is possible to easily remove the unsintered portion.
Application Example 8A three-dimensional forming apparatus according to this application example includes a material supply device serving as a material supply unit that arranges a green sheet obtained by forming a sintering material in which metal powder and a binder are kneaded into a sheet shape on a stage, the material supply device including a sheet holding unit holding the green sheet placed on a supply table and a supply driving unit moving the sheet holding unit relative to the supply table, in which a sintering device serving as a first heating unit that supplies first energy transpiring a part of the green sheet and a second heating unit that supplies second energy capable of sintering a part of the green sheet includes a base, a stage movable three-dimensionally relative to the base, and a heating device heating the green sheet transferred to the stage to be stacked, and in which the first energy is supplied from the first heating unit to the green sheet so that a sintering region to be sintered with the second energy supplied from the second heating unit in the green sheet supplied to the stage by the material supply unit is surrounded.
According to this three-dimensional forming apparatus of this application example, the precise sintering region can be formed by transpiring and removing the green sheet so that the sintering region to be sintered with the first energy, which is a part of the three-dimensional fabricated object, is surrounded. Accordingly, it is possible to form the precise three-dimensional fabricated object.
Application Example 9In the three-dimensional forming apparatus according to the application example described above, the sintering device includes a laser oscillator, a galvano device by which a laser beam from the laser oscillator is radiated to a predetermined radiation position, and a plurality of laser controllers controlling output energy of the laser beam with respect to the green sheet, and the galvano device includes a galvano mirror reflecting the laser beam and a mirror driving unit driving the galvano mirror to reflect the laser beam from the laser oscillator in a predetermined direction.
According to this application example, the green sheet can be heated with high efficiency, and thus a loss of the supplied energy and a heating time are reduced.
Application Example 10A three-dimensional forming apparatus according to this application example includes: a control unit that serves as a control mechanism controlling a stage, a laser oscillator, a galvano device, a laser controller, and a material supply device.
According to this three-dimensional forming apparatus of this application example, it is possible to control the stage, the laser oscillator, the galvano device, the laser controller, and the material supply device, for example, based on the fabrication data of the three-dimensional fabricated object output from a data output apparatus such as a personal computer. Thus, it is possible to obtain the three-dimensional fabricated object with high precision of a finished product.
Application Example 11In the three-dimensional forming apparatus according to the application example described above, the control unit includes a controller operating in cooperation with a driving controller of the stage, a driving controller of the laser oscillator, a driving controller of the galvano device, a driving controller of the laser controller, and a driving controller of the material supply device.
According to this application example, the driving controller of the stage, the driving controller of the laser oscillator, the driving controller of the galvano device, the driving controller of the laser controller, and the driving controller of the material supply device operate in a cooperative manner to be driven. Therefore, even in the forming of a complicated shape, it is possible to form the three-dimensional fabricated object with high efficiency.
The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements.
Hereinafter, embodiments of the invention will be described with reference to the drawings.
First EmbodimentA three-dimensional forming apparatus 1000 illustrated in
The material supply device 200 includes a supply base 210, a supply table 220 that is included to be able to be driven in the Z axis direction in an illustrated gravity direction by a driving unit (not illustrated) included in the supply base 210, and a transfer device 230 that holds one uppermost green sheet among a plurality of green sheets 300 loaded on the supply table 220 and transfers the green sheet to the sintering device 100.
The transfer device 230 includes a sheet holding unit 230a capable of holding the green sheet 300 and supply driving units 230b that move the sheet holding unit 230a relative to the supply table 220 at least in the X axis direction and the Y axis direction. The sheet holding unit 230a includes, for example, a sheet adsorption unit 230c which is a unit capable of holding and separating the green sheet 300 through decompression, suction, or the like, and thus can adsorb and hold the green sheet 300 using the sheet adsorption unit 230c. A method of holding the green sheet 300 of the sheet adsorption unit 230c is not limited to the above-described method. For example, when a raw metal is a magnetic substance, the green sheet may be mechanically held using a magnetic force adsorption method or the like or a pilot hole.
The sintering device 100 includes a base 110, a stage 120 that is included to be able to be driven in the illustrated Z axis direction with respect to the base 110 by a driving device (not illustrated) included in the base 110, and a sample plate 121 that is disposed on the stage 120 and has a heat resistance property to protect the stage 120 from heat energy from a heating mechanism to be described below. The green sheets 300 transferred from the material supply device 200 are stacked and disposed on the sample plate 121. In this example, for the green sheet 300 transferred and stacked in the uppermost layer, a press roller 170 that reciprocates in the X axis direction while pressing the green sheet 300 of the uppermost layer may be included in order to come into close contact with the green sheet 300 of the immediately lower layer. The press roller 170 preferably includes a unit that heats the green sheet 300 in order to improve adhesion between the upper and lower green sheets 300.
A laser oscillator 130 and a galvano device 140 by which a laser beam serving as a heating mechanism radiated from the laser oscillator 130 is radiated to a predetermined radiation position toward the green sheet 300 placed on the sample plate 121 are further included. The galvano device 140 and the driving device (not illustrated) included in the base 110 form a driving unit that can move the laser beam serving as the heating mechanism and the green sheet 300 on the sample plate 121 three-dimensionally relatively.
The galvano device 140 includes a galvano mirror 141 that reflects the laser beam and a mirror driving unit 142 that drives the galvano mirror 141 to reflect an optical axis of the laser beam from the laser oscillator 130 in a predetermined direction.
The three-dimensional forming apparatus 1000 includes a control unit 400 serving as a control mechanism that controls the stage 120, the supply table 220, the laser oscillator 130, the galvano device 140, and the transfer device 230 described above, for example, based on fabrication data for the three-dimensional fabricated object output from a data output device such as a personal computer (not illustrated). Although not illustrated in the drawing, the control unit 400 includes a driving control unit of the stage 120, a driving control unit of the supply table 220, a driving control unit of the laser oscillator 130, a driving control unit of the galvano device 140, a driving control unit of the transfer device 230, and a control unit controlling the driving in cooperation with the driving control units.
In regard to the stage 120 included to be able to be moved to the base 110 and the supply table 220 included to be able to be moved to the supply base 210, signals used to control movement start and stop, a movement direction, a movement amount, a movement speed, and the like of the stage 120 or the supply table 220 are generated based on control signals from the control unit 400 in a stage controller 410 and are transmitted to a driving device (not illustrated) included in the base 110 or the supply base 210 for driving.
In regard to the transfer device 230 included in the material supply device 200, signals used to control movement of the sheet holding unit 230a by the supply driving unit 230b included in the transfer device 230 and holding, separation, or the like of the green sheet 300 with respect to the sheet adsorption unit 230c are generated based on control signals from the control unit 400 in a material supply device controller 240, and thus the transfer of the green sheet 300 to the sintering device 100 is controlled.
In regard to the laser oscillator 130 and the galvano device 140, a laser controller 150 performing control such that at least energy of a different output is supplied to the green sheet 300 supplied to the stage 120 is included in the sintering device 100. The laser controller 150 includes at least a first laser controller 151 and a second laser controller 152.
A first heating unit is formed by the first laser controller 151 and a first laser beam L1 radiated as first energy from the laser oscillator 130 controlled by the first laser controller 151. A second heating unit is configured by the second laser controller 152 and a second laser beam L2 radiated as second energy from the laser oscillator 130 controlled by the second laser controller 152.
That is, one laser oscillator 130 can radiate the first laser beam L1 or the second laser beam L2 with a different output or wavelength toward the green sheet 300 by the two controllers, the first laser controller 151 and the second laser controller 152. Of course, a plurality of the laser oscillators 130 may be included and each laser oscillator may be configured to individually oscillate the first laser beam L1 or the second laser beam L2. The driving control of the galvano device 140 is performed such that a control signal is transmitted from the laser controller 150 to a galvano mirror controller 160 and a radiation direction of the laser beam L1 or L2 of the laser oscillator 130 is oriented to a predetermined position of the green sheet 300 for radiation.
Next, an overview of an operation of the three-dimensional forming apparatus 1000 forming a three-dimensional fabricated object will be described with reference to
As illustrated in
A laser emitted from the laser oscillator 130 is radiated toward the green sheet 300 illustrated in
A signal for oscillating the first laser beam L1 is transmitted from the first laser controller 151 included in the laser controller 150 to the laser oscillator 130 based on an instruction of the control unit 400. Besides, a signal for driving control of the galvano device 140 starts to be generated in the galvano mirror controller 160 and the first laser beam L1 is emitted from the laser oscillator 130. Then, as illustrated in
The first laser beam L1 has first energy with an output by which the metal powder and the binder included in the green sheet 300 can be transpired, and the green sheet 300 is partially removed so that a partially removed portion 2001b is formed along the outer circumference 2001a of a fabrication schedule region of the partial fabricated object 2001. Then, the green sheet 300 is partially removed so that a partially removed portion 2001d is formed along the inner circumference 2001c. A portion surrounded by the partially removed portion 2001b and the partially removed portion 2001d formed in this way is a fabrication raw material 2001e formed in the partial fabricated object 2001, and the green sheet 300a in a state in which the partially removed portions 2001b and 2001d are removed is obtained including the fabrication raw material 2001e.
Then, after the first laser beam L1 is radiated, a signal for oscillating the second laser beam L2 is transmitted from the second laser controller 152 included in the laser controller 150 to the laser oscillator 130 based on an instruction of the control unit 400. Besides, a signal for driving control of the galvano device 140 starts to be generated in the galvano mirror controller 160 and the second laser beam L2 is emitted from the laser oscillator 130. Then, as illustrated in
The second laser beam L2 has second energy with an output by which the metal powder can be bonded by transpiring the binder from the state in which the metal powder and the binder included in the green sheet 300 are kneaded, that is, a metal fabricated object can be formed through sintering. The second laser beam L2 is radiated to the fabrication raw material 2001e. Then, the fabrication raw material 2001e is sintered, so that the partial fabricated object 2001 is formed.
When the first laser beam L1 and the second laser beam L2 are radiated to the green sheet 300, the partially removed portions 2001b and 2001d are formed, and the partial fabricated object 2001 is formed, an unsintered region 300b for which none of the laser beams L1 and L2 are radiated to the green sheet 300 remains. Hereinafter, this region is referred to as an unsintered portion 300b in the green sheet 300.
As described above, the fabrication raw material 2001e with a precise shape is formed by the partially removed portions 2001b and 2001d, and the partial fabricated object 2001 with a precise shape is formed by sintering the fabrication raw material 2001e. Further, the second laser beam L2 radiated at this time, that is, the heat of the second energy, is not transferred to the unsintered portion 300b since the partially removed portions 2001b and 2001d serve as interruption portions. Thus, there is no concern of a partial sintering region being formed in the unsintered portion 300b. Accordingly, it is possible to easily perform a work of removing the finally removed unsintered portion 300b. Further, it is possible to suppress a loss of the raw material when the removed unsintered portion 300b is kneaded as the raw material again.
As described above, the three-dimensional forming apparatus 1000 according to the embodiment includes the laser oscillator 130 serving as the heating unit capable of supplying at least energy with different outputs and the galvano device 140 by which the laser beam radiated from the laser oscillator 130 is radiated to a predetermined radiation position toward the green sheet 300 placed on the sample plate 121. Thus, the single three-dimensional forming apparatus 1000 can efficiently perform different processes, that is, composite processes of the sintering process and the material removal process by the transpiring.
The first laser beam L1 and the second laser beam L2 described above are configured to be radiated toward a region to which the laser beams L1 and L2 are each expected to be radiated by the galvano device 140 by adjusting the output of the laser oscillator 130, but the invention is not limited thereto. For example, a plurality of laser oscillators, a laser oscillator radiating the first laser beam L1 and a laser oscillator radiating the second laser beam L2, may be mounted on arms of a double arm robot and the desired laser beams L1 and L2 may be configured to be radiated to a predetermined region by driving the arms.
The case has been exemplified in which the laser beam is used in the heating unit in the three-dimensional forming apparatus 1000 according to the first embodiment described above, but the invention is not limited thereto. For example, by blowing a hot wind to the green sheet 300 instead of the laser beam, the three-dimensional fabricated object 2000 can be formed. In this case, a hot wind ejecting unit for a temperature corresponding to the first energy and a hot wind ejecting unit for a temperature corresponding to the second energy may be included as units ejecting hot wind with different temperatures. Alternatively, hot wind with different temperatures may be ejected from a single hot wind ejecting unit.
Second EmbodimentA material supply device 500 included in the three-dimensional forming apparatus 1100 illustrated in
In the material supply to the sintering device 100, a control signal is transmitted from the control unit 400 to the stage controller 410, so that the supply table 520 is driven. The supply table 520 is moved up to a position at which the continuous sheet 600a can be delivered to the uppermost layer of the green sheet 300 stacked in the sintering device 100 in the Z axis direction and the X axis direction of a direction in which the sintering device 100 approaches the stage 120 in the state illustrated in
Then, the delivery roller 540 is driven based on a driving signal generated based on the control signal from the control unit 400 by a material supply device controller 550, so that the continuous sheet 600a is delivered to the uppermost layer of the green sheet 300 stacked in the sintering device 100. At this time, the roll holding unit 530 may be configured to be rotated freely in accordance with the delivery of the continuous sheet 600a delivered by the delivery roller 540, or may be configured such that a delivery amount of the delivered continuous sheet 600a is detected by a detection device (not illustrated) and may include a driving unit that rotates the supply material roll 600 by applying the delivery amount of the continuous sheet 600a.
When the continuous sheet 600a is delivered by a predetermined amount to the uppermost layer of the green sheet 300 stacked in the sintering device 100, the first laser beam L1 is instructed to be oscillated from the first laser controller 151 to the laser oscillator 130, the first laser beam L1 emitted from the laser oscillator 130 is reflected in the galvano device 140 and is radiated as a cutting laser beam L11 for cutting the continuous sheet 600a by a size corresponding to a predetermined green sheet 300 to the continuous sheet 600a, so that the continuous sheet 600a is cut out.
In the three-dimensional forming apparatus 1100 according to the embodiment, the green sheet 300 which is a supply material supplied to the sintering device 100 can be supplied to the sintering device 100 in accordance with the shape of a three-dimensional fabricated object so that the green sheet 300 has a necessary minimum size. Accordingly, it is possible to reduce waste of the material and to form a fabricated object with an improved material efficiency, that is, a product.
Third EmbodimentA three-dimensional forming method of forming a three-dimensional fabricated object using the three-dimensional forming apparatus 1000 according to the first embodiment will be described according to a third embodiment.
As illustrated in
In the material preparation process (S2), a predetermined number of green sheets 300 is placed on the supply table 220 included in the material supply device 200. The green sheet 300 is formed by a green sheet forming device 3000 or the like for the green sheet 300, as the schematic configuration is exemplified in
As illustrated in
The raw material M in which the above-described metal powder and binder and a solvent for viscosity adjustment are added and kneaded is input to the raw material supply unit 3100, and a predetermined amount of raw material is sequentially discharged to the transport belt 3200 driven in an illustrated arrow F direction. With the movement of the transport belt 3200 in the F direction, the thickness of the raw material M is equalized by an equalizing roll 3300, the raw material M passes through a subsequent pressurization roller 3400 so that the raw material M has a predetermined thickness for the green sheet 300. Then, the raw material M is cut out in a predetermined length by a cutting unit 3500 to obtain the green sheet 300.
Material Supply ProcessWhen the predetermined number of green sheets 300 are placed on the supply table 220 of the material supply device 200 in the material preparation process (S2), a material supply process (S3) starts. In the material supply process (S3), the material supply device controller 240 generates a driving signal of the transfer device 230 based on a control signal from the control unit 400 and drives the transfer device 230.
First, the sheet holding unit 230a is moved up to a predetermined position, and the uppermost sheet of the green sheets 300 stacked on the supply table 220 is adsorbed and held by the sheet adsorption unit 230c. The sheet holding unit 230a is moved to the sample plate 121 of the sintering device 100 while holding the green sheet 300, the green sheet 300 is detached and separated from the sheet adsorption unit 230c, and the green sheet 300 is placed on the sample plate 121. After the green sheet 300 is placed and separated, the sheet holding unit 230a returns to a standby position of the material supply device 200. Hereinafter, the green sheet 300 placed as a first layer will be described as a first layer green sheet 301.
Partial Removal ProcessWhen the first layer green sheet 301 is placed on the sample plate 121, a partial removal process (S4) starts. As illustrated in
In the partial removal process (S4), the first layer green sheet 301 of the region to which the first energy of the first laser beam L1 is radiated is transpired by radiating the first laser beam L1 illustrated in
Next, the first laser beam L1 is radiated from a radiation start point P12 to the radiation start point P12 along a radiation route R12 based on three-dimensional fabrication data to form a partially removed portion 2001d so that the inner circumference 2001c of the fabrication schedule region of the partial fabricated object 2001 is formed. A portion surrounded by the partially removed portion 2001b and the partially removed portion 2001d formed in this way is the fabrication raw material 2001e of the partially fabricated object 2001, and a first layer green sheet 301a from which the partially removed portions 2001b and 2001d are removed is formed including the fabrication raw material 2001e. That is, in other words, the partially removed portions 2001b and 2001d are formed to surround the circumference of the fabrication raw material 2001e.
Sintering ProcessNext, the process proceeds to a sintering process (S5) in which the second laser beam L2 with the second energy is radiated to the fabrication raw material 2001e formed in the first layer green sheet 301a formed in the partial removal process (S4). The sintering in the sintering process (S5) is a processing mechanism of transpiring the binder from the state in which the metal powder and the binder included in the green sheet 300 are kneaded, bonding the metal powder, and forming a metal fabricated object from the metal powder state.
In the sintering process (S5), as illustrated in
The fabrication raw material 2001e is sintered in the sintering process (S5) from the first layer green sheet 301a from which the partially removed portions 2001b and 2001d are removed in the partial removal process (S4), and thus the partial fabricated object 2001 is formed. The remaining regions, that is, an outside region 301b of the partially removed portion 2001b and an inside region 301c of the partially removed portion 2001d in this example, are regions to which none of the first laser beam L1 and the second laser beam L2 are radiated, that is, are unsintered regions. Hereinafter, the outside region 301b is referred to as a first unsintered portion 301b and the inside region 301c is referred to as a second unsintered portion 301c.
In this way, the sintered partial fabricated object 2001, the first unsintered portion 301b, and the second unsintered portion 301c are formed in the sintering process (S5), so that a first layer 301d is formed as a first single layer. The above-described series of processes from the material supply process (S3) to the sintering process (S5) is a single layer forming process (S100). Then, the sintering process (S5) ends, that is, the single layer forming process (S100) ends and the process proceeds to a subsequent stack number comparison process.
Stack Number Comparison ProcessWhen the first layer 301d including the partial fabricated object 2001 which is the first layer, the first unsintered portion 301b, and the second unsintered portion 301c is formed in the single layer forming process (S100), the process proceeds to a stack number comparison process (S6) of performing comparison with fabrication data obtained in the three-dimensional fabrication data acquisition process (S1). In the stack number comparison process (S6), a stack number N of the green sheets 300 in which partial fabricated objects are formed and which are necessary to form the three-dimensional fabricated object 2000 is compared to a stack number n of the green sheets 300 stacked up to the single layer forming process (S100) immediately before the stack number comparison process (S6). When n<N is determined in the stack number comparison process (S6), the process proceeds to a stacking process of performing the single layer forming process (S100) again.
Stacking ProcessA stacking process (S7) is an instruction process of performing the single layer forming process (S100) again when n<N is determined in the stack number comparison process (S6). The material supply process (S3) which is a start process of the single layer forming process (S100) is performed.
As illustrated in
Then, as illustrated in
As illustrated in
An unsintered portion removal process (S8) is a process of removing portions excluding the three-dimensional fabricated object 2000, that is, the first unsintered portions 310 and the second unsintered portions 320. As the method of removing the unsintered portions 310 and 320, for example, a mechanical removal method or a method of dissolving the binder including the unsintered portions 310 and 320 using a solvent and removing the remaining metal powder can be applied. In the embodiment, the mechanical removal method will be described as an example.
As illustrated in
In the three-dimensional forming method for the three-dimensional fabricated object 2000 according to the above-described third embodiment, the partially removed portions 2001b and 2001d are formed to surround the fabrication raw material 2001e formed as the region in which the partial fabricated object 2001 is formed in the partial removal process (S4) included in the single layer forming process (S100). By forming the partially removed portions 2001b and 2001d in this way, a member transmitting heat generated by the second laser beam L2 is not present in the outer edge of the fabrication raw material 2001e when the fabrication raw material 2001e is sintered with the second laser beam L2 in the sintering process (S5). Therefore, it is possible to obtain the partial fabricated object with a precise shape, that is, the three-dimensional fabricated object 2000.
In the three-dimensional forming method according to the third embodiment, the unsintered portion removal process (S8) is performed after the predetermined stack number N is stacked. Therefore, as illustrated in
For example, as illustrated in
A three-dimensional forming method according to a fourth embodiment will be described. The three-dimensional forming method according to the fourth embodiment is different in that a splitting portion forming process of splitting the unsintered portion 310 or the unsintered portion 320 removed in the unsintered portion removal process (S8) in advance is included in the partial removal process (S4) of the three-dimensional forming method according to the third embodiment. Accordingly, in the description of the three-dimensional forming method according to the fourth embodiment, the same reference numerals are given to the same constituent elements as those of the three-dimensional forming method according to the third embodiment, and the description thereof will be omitted.
In the partial removal process (S40) according to the embodiment, as illustrated in
A splitting portion forming process (S41) of transpiring and removing the element of the green sheet 300 is performed on the obtained outside region 301b of the first layer green sheet 301a by radiating the first energy of the first laser beam L1 to four regions, partially removed portions 301e, 301f, 301g, and 301h, in this example radially toward the outside from the partially removed portion 2001b, as illustrated in
After the partial removal process (S40) including the splitting portion forming process (S41) is performed, the stacking process (S7) and the single layer forming process (S100) are repeated as in the three-dimensional forming method according to the third embodiment. When n=N is determined in the stack number comparison process (S6), layers are formed up to an N-th layer 30Nd including the three-dimensional fabricated object 2000 immediately before the unsintered portion removal process (S8), as illustrated in
In this way, the first unsintered portion 310 is formed by split unsintered portions 310e, 310f, 310g and 310h split by the splitting portions 310a, 310b, 310c, and 310d, and thus the removed portions can be easily broken in a subsequent unsintered portion removal process (S8).
In the above-described splitting portion forming process (S41), the case in which the outside region 301b is split into four portions has been described, but the invention is not limited thereto. The outside region may be split into two or more portions. Splitting portions may be formed in the inside region 301c, and splitting portions may be formed in both regions, the outside region 301b and the inside region 301c.
Claims
1. A three-dimensional forming apparatus comprising:
- a material supply unit that arranges a green sheet obtained by forming a sintering material in which metal powder and a binder are kneaded into a sheet shape on a stage;
- a first heating unit that supplies first energy transpiring a part of the green sheet;
- a second heating unit that supplies second energy capable of sintering a part of the green sheet; and
- a driving unit that is able to move the first heating unit and the second heating unit three-dimensionally relative to the stage,
- wherein the first energy is supplied from the first heating unit to the green sheet so that a sintering region to be sintered with the second energy supplied from the second heating unit in the green sheet supplied to the stage by the material supply unit is surrounded.
2. The three-dimensional forming apparatus according to claim 1, wherein an output of the first energy is different from an output of the second energy.
3. The three-dimensional forming apparatus according to claim 1, wherein the first heating unit and the second heating unit are laser radiation units.
4. A three-dimensional forming method comprising:
- supplying a green sheet obtained by forming a sintering material in which metal powder and a binder are kneaded into a sheet shape;
- forming a single layer by transpiring and removing a part of the green sheet through radiation of first energy to the green sheet to form a removed portion and by radiating second energy toward the green sheet and sintering a part of the green sheet to form a sintered portion;
- stacking the single layer formed in the forming of the single layer as a first single layer and stacking the single layer as a second single layer in the forming of the single layer; and
- removing an unsintered portion from a stacked body including a three-dimensional fabricated object in which the sintered portions are stacked by repeating the stacking of the single layer a predetermined number of times.
5. The three-dimensional forming method according to claim 4, wherein in the removing of the part of the green sheet, the removed portion is formed so that a region in which the sintered portion is formed in the sintering of the part of the green sheet is surrounded.
6. The three-dimensional forming method according to claim 4,
- wherein the first energy and the second energy are lasers, and
- wherein the first energy and the second energy are different in a laser output or a laser wavelength.
7. The three-dimensional forming method according to claim 4, wherein the removing of the part of the green sheet includes forming a splitting portion that splits the unsintered portion to be removed in the removing of the unsintered portion into a plurality of pieces.
8. A three-dimensional forming apparatus comprising:
- a material supply device serving as a material supply unit that arranges a green sheet obtained by forming a sintering material in which metal powder and a binder are kneaded into a sheet shape on a stage, the material supply device including a sheet holding unit holding the green sheet placed on a supply table and a supply driving unit moving the sheet holding unit relative to the supply table,
- wherein a sintering device serving as a first heating unit that supplies first energy transpiring a part of the green sheet and a second heating unit that supplies second energy capable of sintering apart of the green sheet includes a base, a stage movable three-dimensionally relative to the base, and a heating device heating the green sheet transferred to the stage to be stacked, and
- wherein the first energy is supplied from the first heating unit to the green sheet so that a sintering region to be sintered with the second energy supplied from the second heating unit in the green sheet supplied to the stage by the material supply unit is surrounded.
9. The three-dimensional forming apparatus according to claim 8,
- wherein the sintering device includes a laser oscillator, a galvano device by which a laser beam from the laser oscillator is radiated to a predetermined radiation position, and a plurality of laser controllers controlling output energy of the laser beam with respect to the green sheet, and
- wherein the galvano device includes a galvano mirror reflecting the laser beam and a mirror driving unit driving the galvano mirror to reflect the laser beam from the laser oscillator in a predetermined direction.
10. A three-dimensional forming apparatus comprising:
- a control unit that serves as a control mechanism controlling a stage, a laser oscillator, a galvano device, a laser controller, and a material supply device.
11. The three-dimensional forming apparatus according to claim 10, wherein the control unit includes a controller operating in cooperation with a driving controller of the stage, a driving controller of the laser oscillator, a driving controller of the galvano device, a driving controller of the laser controller, and a driving controller of the material supply device.
Type: Application
Filed: Oct 7, 2015
Publication Date: Apr 14, 2016
Inventor: Tomoyuki KAMAKURA (Matsumoto-shi)
Application Number: 14/877,641